<template>
    <div class="app-container">
    <!-- 输入表单 -->
    <el-form label-width="120px">
        <el-form-item label="讲师名称">
            <el-input v-model="teacher.name" />
        </el-form-item>
        <el-form-item label="入驻时间">
            <el-date-picker v-model="teacher.joinDate" value-format="yyyy-MM-dd" />
        </el-form-item>
        <el-form-item label="讲师排序">
            <el-input-number v-model="teacher.sort" :min="0"/>
        </el-form-item>
        <el-form-item label="讲师头衔">
            <el-select v-model="teacher.level">
                <!--
                数据类型一定要和取出的json中的一致，否则没法回填
                因此，这里value使用动态绑定的值，保证其数据类型是number
                -->
                <el-option :value="1" label="高级讲师"/>
                <el-option :value="2" label="首席讲师"/>
            </el-select>
        </el-form-item>
        <el-form-item label="讲师简介">
            <el-input v-model="teacher.intro"/>
        </el-form-item>
        <el-form-item label="讲师资历">
        <el-input v-model="teacher.career" :rows="10" type="textarea"/>
        </el-form-item>
        <!-- 讲师头像：TODO -->
        <el-form-item label="讲师头像">
        <el-upload
        class="avatar-uploader"
        :action="BASE_API+'/admin/oss/file/upload?module=avatar'"
        :show-file-list="false"
        :on-success="handleAvatarSuccess"
        :on-error="handleAvatarError"
        :before-upload="beforeAvatarUpload">
        <img v-if="teacher.avatar" :src="teacher.avatar" class="avatar">
        <i v-else class="el-icon-plus avatar-uploader-icon"></i>
        </el-upload>
        </el-form-item>
        <el-form-item>
            <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate()">保存</el-button>
        </el-form-item>
    </el-form>
    </div>
</template>

<script>
import teacherApi from '@/api/teacher'
export default {
    data(){
        return {
            teacher:{
                sort:1,
                level:1
            },
            saveBtnDisabled:false, //设置按钮
            BASE_API: process.env.BASE_API
        }
    },
    created(){
        if(this.$route.params.id){
            this.fetchDataById(this.$route.params.id);
        }
    },
    methods:{
        saveOrUpdate(){
            this.saveBtnDisabled = true;
            if(!this.teacher.id){
                this.saveData();
            }else{
                this.updateData();
            }
        },
        saveData(){
            teacherApi.save(this.teacher).then(response =>{
                this.$message({
                    message:response.message,
                    type:'success'
                });
                this.saveBtnDisabled = true;
                this.$router.push({path:'/teacher'});
            })
        },
        fetchDataById(id){
            teacherApi.getById(id).then(response =>{
                this.teacher = response.data.item;
            });
        },
        updateData(teacher){
            teacherApi.updateById(this.teacher).then(response =>{
                this.$message({
                    type:'success',
                    message:response.message
                });
                this.$router.push({path:'/teacher'});
            })
        },
        //文件上传成功
        handleAvatarSuccess(response){
            if(response.success){
                this.teacher.avatar = response.data.url;
            //强制重新渲染
            this.$forceUpdate();
            }else{
                this.$message.error(response.message)
            }
            
        },
        //文件上传前的校验
        beforeAvatarUpload(file){
            const isJPG = file.type === 'image/jpeg';
            const isLt2M = file.size / 1024 / 1024 < 2;

            if (!isJPG) {
            this.$message.error('上传头像图片只能是 JPG 格式!');
            }
            if (!isLt2M) {
            this.$message.error('上传头像图片大小不能超过 2MB!');
            }
            return isJPG && isLt2M;
        },
        //文件上传失败
        handleAvatarError(){
            this.$message.error('哎呀，断网啦');
        }
    }
}
</script>  

<style>
  .avatar-uploader .el-upload {
    border: 1px dashed #d9d9d9;
    border-radius: 6px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
  }
  .avatar-uploader .el-upload:hover {
    border-color: #409EFF;
  }
  .avatar-uploader-icon {
    font-size: 28px;
    color: #8c939d;
    width: 178px;
    height: 178px;
    line-height: 178px;
    text-align: center;
  }
  .avatar {
    width: 178px;
    height: 178px;
    display: block;
  }
</style>